A multi-dimensional electric field type liquid crystal display is a kind of displays that has been widely used, and it generally includes two parts: a Thin Film Transistor (TFT) array substrate and a color filter substrate. A multi-dimensional electric field type liquid crystal display in which both pixel electrodes and common electrodes are formed on a thin film transistor array substrate has the characteristics of wide viewing angle and high opening ratio.
A thin film transistor array substrate is divided into a display zone and a non-display zone. In a thin film transistor structure in a conventional thin film transistor array substrate, as illustrated in FIG. 1, a gate electrode 12, an insulating layer 13, a semiconductor layer 14, a doped semiconductor layer 15, a source electrode 16, a drain electrode 17, a passivation layer 18 and a common electrode wire 19 are sequentially formed at a non-display zone on a substrate 11 from bottom to top, a common electrode 110, an insulating layer 13, a passivation layer 18 and a pixel electrode 111 are sequentially formed at a display zone B on the substrate 11 from bottom to top; and on the passivation layer 18 at the non-display zone A, there is provided a via hole C, through which the pixel electrode 111 is electrically connected to the drain electrode 17. When a FFS mode liquid crystal display operates, the pixel electrode 111 and the common electrode 110 are electrically conductive, and a horizontal electric field is formed by them.
In the above thin film transistor array substrate, the semiconductor layer is of a photosensitive material, and is susceptible to external light. A backlight source cannot be well sheltered by a thin film transistor in the array substrate and light tends to irradiate the semiconductor layer, resulting in a poor light-shielding processing of the bottom-gate, FFS mode thin film transistor array substrate. Thus, the display effect of the liquid crystal display is degraded.